Exhaust oxygen sensors have been used for many years in automotive vehicles to sense the presence of oxygen in exhaust gasses, for example, to sense when an exhaust gas content switches from rich to lean or lean to rich. One known type of oxygen sensor includes a flat plate oxygen sensor formed of various layers of ceramic and electrolyte materials laminated and sintered together with electrical circuit and sensor traces placed between the layers in a known manner.
Because automotive oxygen sensors are mounted to members of the vehicle exhaust flow system, the sensors must be durable, able to withstand vibration and jarring such as would occur during installation and normal vehicle operation and able to withstand shock from the occasional stone or other small road debris that may happen to be thrown at the sensor, for example, by the vehicle's tires.